The invention relates to a method for the at least partial detachment or separation of a sealing film or foil that is sealingly attached to a rim of a neck of a container, vessel, bottle, or the like, which rim has a circular sealing surface and the neck has an male thread and a center axis, and a screw cap having a female thread complementary to the male thread and capable of being screwed down onto the male thread of the neck sealed in the aforementioned manner and the cap can be unscrewed at any later point in time, as desired.
The invention further relates to a screw cap for the implementation of this method.
If it is required to protect possibly sterile contents of, say, a bottle for a prolonged period of time from outside influences, for example from the penetration of microbes or other contaminants, it is still necessary, as in the prior art, to apply a sealing film that is impermeable to the aforementioned substances to the rim of the mouth of the bottle in such a way that the actual sealing surface also cannot be penetrated by these substances.
In general, aluminum foils that have a coating of, for example, HDPE (high duty polyethylene) or a similar material on their sealing side are used for standard plastics material bottles made of, for example, polyethylene (PE) or polyethylene terephthalate (PET). After such a sealing film is placed on the rim of the bottle, the coating of the sealing film is welded to the rim of the bottle. The sealing film then adheres firmly and forms an impervious seal with the rim. Gluing rather than welding is another option.
According to this prior art, a screw cap is screwed down to protect the sealing film, and the user then loosens or peels off this film by hand after unscrewing the screw cap and pulling off any originality seal ring that may be present, on the screw cap in order to allow access to the contents of the container. In particular when only part of the bottle's contents have been used, the bottle with its remaining contents can then be resealed by screwing the screw cap back on.
With every bottle containing, say, fresh milk or juice, the consumer finds it awkward not only to have to unscrew the screw cap, but also to have to grasp a piece of the sealing film projecting beyond the rim of the neck of the bottle and then to peel off the sealing film, an operation that requires a certain amount of dexterity.